Adigraph (from Ancient Greekδίς (dís)'double' and γράφω (gráphō)'to write') ordigram is a pair ofcharacters used in theorthography of alanguage to write either a singlephoneme (distinct sound), or a sequence of phonemes that does not correspond to the normal values of the two characters combined.
Some digraphs represent phonemes that cannot be represented with a single character in the writing system of a language, like⟨ch⟩ in Spanishchico andocho. Other digraphs represent phonemes that can also be represented by single characters. A digraph that shares its pronunciation with a single character may be a relic from an earlier period of the language when the digraph had a different pronunciation, or may represent a distinction that is made only in certaindialects, like the English⟨wh⟩. Some such digraphs are used for purelyetymological reasons, like⟨ph⟩ in French.
In some orthographies, a digraph (or atrigraph) is considered to constitute aletter, which means that it has its own place in thealphabet and cannot be separated into its constituentgraphemes for purposes ofsorting,abbreviating, orhyphenating words. Digraphs are used in someromanization schemes, e.g.⟨zh⟩ as a romanisation ofRussian⟨ж⟩.
Thecapitalisation of digraphs can vary, e.g.⟨sz⟩ in Polish is capitalized⟨Sz⟩ and⟨kj⟩ inNorwegian is capitalized⟨Kj⟩, while⟨ij⟩ inDutch is capitalized⟨IJ⟩ and word initial⟨dt⟩ inIrish is capitalized⟨dT⟩.
Digraphs may also develop intoligatures, but the two concepts are distinct; a digraph's essential feature is its sound, while a ligature is visual, graphically fusing two characters into one, e.g. when⟨o⟩ and⟨e⟩ become⟨œ⟩, e.g. as inFrenchcœur "heart".
Digraphs may consist of two different characters (heterogeneous digraphs) or two instances of the same character (homogeneous digraphs). In the latter case, they are generally calleddouble (ordoubled)letters.
Doubledvowel letters are commonly used to indicate along vowel sound. This is the case inFinnish andEstonian, for instance, where⟨uu⟩ represents a longer version of the vowel denoted by⟨u⟩,⟨ää⟩ represents a longer version of the vowel denoted by⟨ä⟩, and so on. InMiddle English, the sequences⟨ee⟩ and⟨oo⟩ were used in a similar way, to represent lengthened "e" and "o" sounds respectively; both spellings have been retained in modernEnglish orthography, but theGreat Vowel Shift andother historical sound changes mean that the modern pronunciations are quite different from the original ones.
Doubledconsonant letters can also be used to indicate a long orgeminated consonant sound. InItalian, for example, consonants written double are pronounced longer than single ones. This was the original use of doubled consonant letters inOld English, but during theMiddle English andEarly Modern English period, phonemic consonant length was lost and a spelling convention developed in which a doubled consonant serves to indicate that a preceding vowel is to be pronounced short. In modern English, for example, the⟨pp⟩ oftapping differentiates the first vowel sound from that oftaping. In rare cases, doubled consonant letters represent a true geminate consonant in modern English; this may occur when two instances of the same consonant come from differentmorphemes, for example⟨nn⟩ inunnatural (un+natural) or⟨tt⟩ incattail (cat+tail).
In some cases, the sound represented by a doubled consonant letter is distinguished in some other way than length from the sound of the corresponding single consonant letter:
In several languages of western Europe, including English,French,Portuguese and Catalan, the digraph⟨ss⟩ is used between vowels to represent the voiceless sibilant/s/, since an⟨s⟩ alone between vowels normally represents the voiced sibilant/z/.
In Spanish, Portuguese, Catalan and Basque,⟨rr⟩ is used between vowels for thealveolar trill/r/, since an⟨r⟩ alone between vowels represents analveolar flap/ɾ/ (the two are different phonemes in those languages).
In Spanish, the digraph⟨nn⟩ formerly indicated/ɲ/ (apalatal nasal); it developed into theletter ñ.
InBasque, double consonant letters generally markpalatalized versions of the single consonant letter, as in⟨dd⟩,⟨ll⟩,⟨tt⟩. However,⟨rr⟩ is a trill that contrasts with the single-letter flap, as in Spanish, and the palatal version of⟨n⟩ is written⟨ñ⟩.
In several European writing systems, including the English one, the doubling of the letter⟨c⟩ or⟨k⟩ is represented as the heterogeneous digraph⟨ck⟩ instead of⟨cc⟩ or⟨kk⟩ respectively. In native German words, the doubling of⟨z⟩, which corresponds to/ts/, is replaced by the digraph⟨tz⟩.
Some languages have a unified orthography with digraphs that represent distinct pronunciations in different dialects (diaphonemes). For example, inBreton there is a digraph⟨zh⟩ that represents[z] in most dialects, but[h] inVannetais. Similarly, theSaintongeais dialect of French has a digraph⟨jh⟩ that represents[h] in words that correspond to[ʒ] in standard French. Similarly, Catalan has a digraph⟨ix⟩ that represents[ʃ] inEastern Catalan, but[jʃ] or[js] inWestern Catalan–Valencian.
The pair of letters making up a phoneme are not always adjacent. This is the case with Englishsilent e. For example, the sequencea_e has the sound/eɪ/ in Englishcake. This is the result of three historical sound changes:cake was originally/kakə/, theopen syllable/ka/ came to be pronounced with along vowel, and later the finalschwa dropped off, leaving/kaːk/. Later still, the vowel/aː/ became/eɪ/. There are six such digraphs in English,⟨a_e, e_e, i_e, o_e, u_e, y_e⟩.[1]
However, alphabets may also be designed with discontinuous digraphs. In theTatarCyrillic alphabet, for example, the letterю is used to write both/ju/ and/jy/. Usually the difference is evident from the rest of the word, but when it is not, the sequenceю...ь is used for/jy/, as inюнь/jyn/ 'cheap'.
TheIndic alphabets are distinctive for their discontinuous vowels, such as Thai เ...อ/ɤː/ in เกอ/kɤː/. Technically, however, they may be considereddiacritics, not full letters; whether they are digraphs is thus a matter of definition.
Some letter pairs are not digraphs but might be interpreted as digraphs because ofcompounding: e.g.hogshead andcooperate (the latter case ofvowel hiatus is also calleddiaeresis). In English, they are often unmarked and must therefore be memorized, or more likely deduced, as exceptions. Some authors, however, indicate it either by breaking up the digraph with ahyphen, as inhogs-head,co-operate, or, in case of a vowel hiatus, with adiaeresis diacritic mark, as incoöperate (thisuse of two dots in English is now archaic but continues to be used extensively in some other languages). When it occurs in names such asClapham, Townshend, and Hartshorne, it is never marked in any way. Positional alternative glyphs may help to disambiguate in certain cases: when round⟨s⟩ was used as a final variant of long⟨ſ⟩, and the English digraph for/ʃ/ would always be⟨ſh⟩.
Similar ambiguity also occurs frequently in German, where it is also unmarked and left to the reader to deduce.
InRomansh, a hyphen is used to distinguish⟨s-ch⟩ from⟨sch⟩.
In Dutch, a diaresis is frequently used to parse⟨eee⟩.
Inromanization of Japanese, the constituent sounds (morae) are usually indicated by digraphs, but some are indicated by a single letter, and some with a trigraph. The case of ambiguity is the syllabicん (orン) , which is written asn (or sometimesm), except before vowels ory where it is followed by anapostrophe asn’. For example, the given name じゅんいちろう is romanized as Jun’ichirō, so that it is parsed as "Ju-n-i-chi-rou", rather than as "Ju-ni-chi-rou". A similar use of the apostrophe is seen inpinyin where 嫦娥 is writtenChang'e because the g belongs to the final (-ang) of the first syllable, not to the initial of the second syllable. Without the apostrophe, Change would be understood as the syllable chan (final -an) followed by the syllable ge (initial g-).
In some languages, certain digraphs andtrigraphs are counted as distinct letters in themselves, and assigned to a specific place in thealphabet, separate from that of the sequence of characters that composes them, for purposes oforthography andcollation:
In theCzech andSlovak alphabet,⟨ch⟩ is treated as a distinct letter, coming after⟨h⟩ in the alphabet. Also, in theSlovak alphabet the relatively rare digraphs⟨dz⟩ and⟨dž⟩ are treated as distinct letters.
In theDanish and Norwegian alphabet, the former digraph⟨aa⟩, where it appears in older names, is sorted as if it were the letter⟨å⟩, which replaced it.
In theNorwegian alphabet, there are several digraphs and letter combinations representing an isolated sound.
In theDutch alphabet, the digraph⟨ij⟩ is sometimes written as aligature and may be sorted with⟨y⟩ (in theNetherlands, though not usually inBelgium); however, regardless of where it is used, when a Dutch word starting with⟨ij⟩ is capitalized, the entire digraph is capitalized (IJmeer,IJmuiden). OtherDutch digraphs are never treated as single letters.
InHungarian, the digraphs⟨cs⟩,⟨dz⟩,⟨gy⟩,⟨ly⟩,⟨ny⟩,⟨sz⟩,⟨ty⟩,⟨zs⟩, and the trigraph⟨dzs⟩, have their own places in the alphabet (where e.g.⟨ny⟩ comes right after⟨n⟩)
InSpanish, the digraphs⟨ch⟩ and⟨ll⟩ were formerly treated as distinct letters, but are now split into their constituent letters.
InWelsh, the alphabet includes the digraphs⟨ch⟩,⟨dd⟩,⟨ff⟩,⟨ll⟩,⟨ng⟩,⟨ph⟩,⟨rh⟩,⟨th⟩. However,⟨mh⟩,⟨nh⟩ and⟨ngh⟩, which representmutated voiceless consonants, are not treated as distinct letters.
In the romanization of several Slavic countries that use the Cyrillic script, letters like ш, ж, and ю might be written as sh, zh and yu, however sometimes the result of the romanization might modify a letter to be a diacritical letter instead of a digraph.
InMaltese, two digraphs are used,⟨għ⟩ which comes right after⟨g⟩, and⟨ie⟩ which comes right after⟨i⟩.
Most other languages, including most of the Romance languages, treat digraphs as combinations of separate letters for alphabetization purposes.
English has both homogeneous digraphs (doubled letters) and heterogeneous digraphs (digraphs consisting of two different letters). Those of the latter type include the following:
⟨wh⟩ represents/hw/ in some conservative dialects;/w/ in other dialects (while); and/h/ in a few words in which it is followed by⟨o⟩, such aswho andwhole. See alsoPhonological history of⟨wh⟩.
⟨zh⟩ represents/ʒ/ in words transliterated from Slavic languages[which?], and in American dictionary pronunciation spelling.
⟨ci⟩ usually appears as/ʃ/ before vowels, like infacial andartificial. Otherwise it is/si/ as infancier andicier or/sɪ/ as inacid andrancid.
⟨wr⟩ represents/r/. Originally, it stood for alabialized sound, while⟨r⟩ without⟨w⟩ was non-labialized, but the distinction has been lost in most dialects, the two sounds merging into a singlealveolar approximant,allophonically labialized at the start of syllables, as inred[ɹʷɛd]. See alsorhotic consonant.
⟨qu⟩ usually represents/kw/;⟨q⟩ is conventionally followed by⟨u⟩ and a vowel letter as inquick, withsome exceptions.
Digraphs may also be composed of vowels. Some letters⟨a, e, o⟩ are preferred for the first position, others for the second⟨i, u⟩. The latter haveallographs⟨y, w⟩ inEnglish orthography.
The digraph⟨aa⟩ represented/ɔ/ until 1917 in Norway and 1948 in Denmark, but is today spelt⟨å⟩. The digraph is still used in older names, but sorted as if it were the letter with the diacritic mark.
InNorwegian, several sounds can be represented only by a digraph or a combination of letters. They are the most common combinations, but extreme regional differences exists, especially those of theeastern dialects. A noteworthy difference is theaspiration of⟨rs⟩ in eastern dialects, where it corresponds to⟨skj⟩ and⟨sj⟩. Among many young people, especially in the western regions of Norway and in or around the major cities, the difference between/ç/ and/ʃ/ has been completely wiped away and are now pronounced the same.
⟨ll⟩ is traditionally pronounced/ʎ/, but in dialects withyeísmo is pronounced/ʝ/
⟨ch⟩ represents/tʃ/ (voiceless postalveolar affricate). Since 2010, neither is considered part of the alphabet. They used to be sorted as separate letters, but a reform in 1994 by theSpanish Royal Academy has allowed that they be split into their constituent letters for collation. The digraph⟨rr⟩, pronounced as a distinctalveolar trill, was never officially considered to be a letter in the Spanish alphabet, and the same is true⟨gu⟩ and⟨qu⟩ (for/ɡ/ and/k/ respectively before⟨e⟩ or⟨i⟩).
⟨rh⟩ represents/r̥/ (voiceless alveolar trill), pronounced roughly like the combinationhr (but again in some words it represents two separate letters, and is pronounced/rh/).
⟨ph⟩ also represents/f/ (voiceless labiodental fricative) but, in modern orthography, is used only for the aspirate mutation of words starting with⟨p⟩.
The digraphs listed above represent distinct phonemes and are treated as separate letters for collation purposes. On the other hand, the digraphs⟨mh⟩,⟨nh⟩, and the trigraph⟨ngh⟩, which stand forvoiceless consonants but occur only at the beginning of words as a result of thenasal mutation, are not treated as separate letters, and thus are not included in the alphabet.
Some words contain three or four consecutive⟨D⟩s or⟨L⟩s. In these cases hyphens are often used to indicate how the characters should be grouped into digraphs.
Modern Slavic languages written in theCyrillic alphabet make little use of digraphs apart from⟨дж⟩ for/dʐ/,⟨дз⟩ for/dz/ (in Ukrainian, Belarusian, and Bulgarian), and⟨жж⟩ and⟨зж⟩ for the uncommon Russian phoneme/ʑː/. In Russian, the sequences⟨дж⟩ and⟨дз⟩ do occur (mainly in loanwords) but are pronounced as combinations of an implosive (sometimes treated as an affricate) and a fricative; implosives are treated as allophones of the plosive/d̪/ and so those sequences are not considered to be digraphs. Cyrillic has few digraphs unless it is used to write non-Slavic languages, especiallyCaucasian languages.
Because vowels are not generally written, digraphs are rare inabjads like Arabic. For example, ifsh were used forš, then the sequencesh could mean eitherša orsaha. However, digraphs are used for theaspirated andmurmured consonants (those spelled withh-digraphs in Latin transcription) in languages ofSouth Asia such asUrdu that are written in theArabic script by a special form of the letterh, which is used only for aspiration digraphs, as can be seen with the following connecting(kh) and non-connecting(ḍh) consonants:
They are called "diphthongs" inGreek; in classical times, most of them representeddiphthongs, and the name has stuck.
γγ (gg) represents/ŋɡ/ or/ɡ/
τσ (ts) represents the affricate/ts/
τζ (tz) represents the affricate/dz/
Initialγκ (gk) represents/ɡ/
Initialμπ (mp) represents/b/
Initialντ (nt) represents/d/
Ancient Greek also had the "diphthongs" listed above although their pronunciation in ancient times is disputed. In addition, Ancient Greek also used the letter γ combined with a velar stop to produce the following digraphs:
In addition,palatal consonants are indicated with the vowel letterι, which is, however, largely predictable. When/n/ and/l/ are not palatalized beforeι, they are writtenνν andλλ.
InBactrian, the digraphsββ,δδ, andγγ were used for/b/,/d/, and/ŋg/ respectively.
In theHebrew alphabet,תס andתש may sometimes be found forצ/ts/. Modern Hebrew also uses digraphs made with the׳ symbol for non-native sounds:ג׳/dʒ/,ז׳/ʒ/,צ׳/tʃ/; and other digraphs of letters when it is written without vowels:וו for a consonantal letterו in the middle of a word, andיי for/aj/ or/aji/, etc., that is, a consonantal letterי in places where it might not have been expected.Yiddish has its own tradition of transcription and so uses different digraphs for some of the same sounds:דז/dz/,זש/ʒ/,טש/tʃ/, andדזש (literallydzš) for/dʒ/,וו/v/, also available as a singleUnicode characterװ,וי or as a single character in Unicodeױ/oj/,יי orײ/ej/, andײַ/aj/. The single-character digraphs are called "ligatures" in Unicode.י may also be used following a consonant to indicate palatalization in Slavic loanwords.
MostIndic scripts have compound voweldiacritics that cannot be predicted from their individual elements. That can be illustrated withThai in which the diacritic เ, pronounced alone/eː/, modifies the pronunciation of other vowels:
single vowel sign:
กา
/kaː/,
เก
/keː/,
กอ
/kɔː/
vowel sign plus เ:
เกา
/kaw/,
แก
/kɛː/,
เกอ
/kɤː/
In addition, the combination รร is pronounced/a/ or/an/, there are some words in which the combinations ทร and ศร stand for/s/ and the letter ห, as a prefix to a consonant, changes its tonic class to high, modifying the tone of the syllable.
Twokana may be combined into aCV syllable by subscripting the second; the convention cancels the vowel of the first. That is commonly done forCyV syllables calledyōon, as in ひょ (ひよ)hyo⟨hiyo⟩. They are not digraphs since they retain the normal sequential reading of the two glyphs. However, some obsolete sequences no longer retain that reading, as in くゎkwa, ぐゎgwa, and むゎmwa, now pronouncedka, ga, ma. In addition, non-sequenceable digraphs are used for foreign loans that do not follow normal Japaneseassibilation patterns, such as ティti, トゥtu, チェtye / che, スェswe, ウィwi, ツォtso, ズィzi. (Seekatakana andtranscription into Japanese for complete tables.)
Long vowels are written by adding the kana for that vowel, in effect doubling it. However, longō may be written eitheroo orou, as in とうきょうtoukyou[toːkʲoː] 'Tōkyō'. For dialects that do not distinguishē andei, the latter spelling is used for a longe, as in へいせいheisei[heːseː] 'Heisei'. In loanwords,chōonpu, a line following the direction of the text, as in ビールbīru[biːru]bīru 'beer'. With the exception of syllables starting withn, doubled consonant sounds are written by prefixing a smaller version oftsu (written っ and ッ in hiragana and katakana respectively), as in きってkitte 'stamp'. Consonants beginning with n use the kanan character (written ん or ン) as a prefix instead.
There are several conventions ofOkinawan kana that involve subscript digraphs or ligatures. For instance, in the University of the Ryukyu's system, ウ is/ʔu/, ヲ is/o/, but ヲゥ (ヲウ) is/u/.
As was the case in Greek, Korean has vowels descended from diphthongs that are still written with two letters. Those digraphs, ㅐ/ɛ/ and ㅔ/e/ (also ㅒ/jɛ/, ㅖ/je/), and in some dialects ㅚ/ø/ and ㅟ/y/, all end in historical ㅣ/i/.
Hangul was designed with a digraph series to represent the "muddy" consonants: ㅃ*[b], ㄸ*[d], ㅉ*[dz], ㄲ*[ɡ], ㅆ*[z], ㆅ*[ɣ]; also ᅇ, with an uncertain value. Those values are now obsolete, but most of the doubled letters were resurrected in the 19th century to write consonants that did not exist when hangul was devised: ㅃ/p͈/, ㄸ/t͈/, ㅉ/t͈ɕ/, ㄲ/k͈/, ㅆ/s͈/.
Digraphs sometimes come to be written as a ligature. Over time, the ligatures may evolve into new letters or letters with diacritics. For examplesz becameß in German, and "nn" becameñ in Spanish.
Generally, a digraph is simply represented using two characters inUnicode.[2] However, for various reasons, Unicode sometimes provides a separatecode point for a digraph, encoded as a single character.
